European patent EP 3 42 343 B1 discloses a roller hearth furnace for the heat treatment of small metal and ceramic parts, in which a roller conveyor is constructed from several, juxtaposed rollers. The ends of said rollers are connected to journals, which are mounted in each case one bearing beam module at both ends of the rollers. There are e.g. five rollers mounted on either side in in each case one bearing beam module. On the drive side the bearing beam has devices for receiving the drive journals of rollers and is located within a side wall of the roller hearth furnace. The rollers of a bearing beam module can be adjusted through the adjustment of the bearing beam relative to the side wall. The bearing beam module can be disassembled in its entirety from the roller hearth furnace. The solution described therein is particularly advantageous for furnaces having a roller spacing of less than 50 mm. However, the rollers cannot be individually replaced.
The problem of the invention is to provide a driving apparatus for rollers of roller hearth furnaces, which permits in an easy manner the removal of individual rollers. In addition, a driving apparatus is to be provided, which can be sealed without difficulty against gas losses of the roller hearth furnace.